From essential results have been obtained since 1971 in collaborative studies with E.N.S.A.I.A. de Nancy, F.N.I.E. et I.N.R.A. d'Antibes. If you have a nitrates low level in carrots, with average lower than 250-300 mg/kg; its necessary to choose ground with poor amount of organic matter (about less than 2%). Otherwise the practice of a strong irrigation, 15 days before the harvest, can lower nitrate level in quantity.